Protector for propeller-blades



S. HEATH.

PROTECTOR son rnormsn BLADES.

APPLICATIGI FILED SEPT. II. 1.9,".

Patamnl Kay 11, 1920.

SPENCER HEATH, OF BALTIMORE, MARYLAND.

PROTECTOR FOR PROPELLER-BLADES.

Specification of Letters Patent.

Patented May 11, 1920.

Application flied September 18, 1918. Serial No. 254,692.

To all whom it ma concern:

Be it known t at I, Srmvoen HEATH, a citizen of the United States, residin at Baltimore, and State of Maryland, ave invented new and useful Improvements in Protectors for PropellerBlades, of which the following is a specification.

My invention relates to the protection of frail and thin edges of flexible members, such as the advance edges of the blades of aeronautical propellers. These propellers when constructed of wood are subject to damage and injury along the advance edges and it is, therefore, often desirable to protect these edges b sheet metal secured along the blades on bot faces adjacent said edges. It has been found difficult to fit this sheet metal to the form of the blades and the curvature of the edges, and, moreover, the constant and rapid bendin of the blades during use causes fatigue 0 the sheet metal and consequently cracking and breaking of the same.

In carrying my invention into effect I aply to the edge of the propeller blade to Be protected a series of short length protecting members, each member covering the edgeand the adjacent faces of the blade to the desired distance from the edge. Each member is secured to the blade .and overla s an ad'acent member so that the blade e go is fully protected and yet the bending may occur without causing the cracking of the metal.

The invention consists in the novel construction and arrangement of parts hereinafter described and claimed, and shown in the accompanying drawing, and the details and advantages of the construction will be fully understood by reference to the following description. v

In the drawings Figure 1 is a face of the propeller blade having a protectin means for an edge thereof constructed an arranged in accordance with my invention;

Fig. 2 is a sectional view of the same taken on the line 22 of Fig. 1;

Fig. 3 shows one of the sections before being applied to the blade.

Referring to the drawings, 10 indicates the individual members of a series of short protecting members secured to the advance edge 11 of the propeller blade 12. These members are made of sheet material preferably sheet metal, such as brass, and may be given any desired shape in outline. Those shown are elliptical and are bent around the advance edge of the blade so as to protect said edge and be secured to and cover the blade faces adjacent thereto. Each member of the series overlaps the adjacent member toward the end of the blade,

so that air and water thrown outwardl by centrifugal action during the action of the propeller is shed from one member to the next.

Each member may be outline, as above indicate but I prefer to so form each member as to provide a less width toward the ends thereof than at the central portion, the elliptical form being a very satisfactory one and the one chosen for the illustration. Each member is independently secured to the blade by screws or rivets or in any other suitable manner.

Although each member or section may be of any preferred length, I prefer to make them comparatively s ort, and each succeeding member toward the outer end of the blade may be of less length than the preceding member in accordance with the degree of bending of the blade. The end section 13, however, is preferably made different from the others and incloses both the blade, as

given any desired faces and the entire end of shown.

The invention will be fully understood from the foregoing but it may be observed that in operation the sections clingclosely to the blade and allow the bending of the latter without bending of the sections to any appreciable extent. hese sections may be considered an analogy to fish scales in this respect, and in practlce the construction is found to be highly eflicient and satisfactory.

While I have described a s ecific embodiment of the invention for t e purpose of illustrating the same,it will be understood that many modifications and changes may be made without departing from the spirit of the invention and all such modifications I aim to cover by the appended claims.

Havin thus described my invention what I- cfitim as new and desire to secure by Letters Patent is 1. The combination with a flexible propeller blade, of an edge protector therefor comprising a series of sections of sheet material covering the blade edge and face portions adjacent thereto.

2. The combination with a flexible pro of an edge protector therefor peller blade,

of overlapping sections com rising a series of s set material.

3. The combination with a flexible propeller blade, of an edge protector therefor comprising a series of sections of sheet material covering the blade edge and face portions adjacent thereto, the end portion of each section overlapping the end portion of the adjacent section toward the end of the blade.

4. The combination with a flexible propeller blade, of an edge protector therefor comprising a series of sections of sheet material independentl secured to the blade and covering the b ade edge and face portions adjacent thereto.

5. The combination with a flexible propeller blade, of an edge protector therefor comprising a series of sections of sheet ma terial covering the blade edge and face portions adjacent thereto the end section covering and inclosing the entire end of the blade.

6. The combination with a flexible propeller blade, comprising a series of sections of sheet material covering the blade edge and face portions adjacent thereto the end portion of each section overlapping the end portion of the adjacent section toward the end of the of an edge protector therefor.

blade, and the end section covering and inclosinthe entire end of the blade.

7. he combination with a flexible propeller blade, of an edge protector therefor comprising a series of sections of sheet material covering the blade edge and face portions adjacent thereto, the width of the portion of edge section on the blade faces being less at the ends than in the central part of the section.

8. The combination with a flexible propeller blade, of a rotector for the advance edges of said bla e comprising a series of sections of sheet metal covering the blade edge and face portionsad'acent thereto.

9. The combination wit a flexible propeller blade, of an edge protector therefor comprising a series of short length protectmg members secured to the edge of the blade.

10. The combination with a propeller blade of a sheathing therefor com rising a plurality of plates or sections 0 channel shape in cross-section, said plates embracing one edge of the blade and having overlapping edges, and means for securing the sheathing to the blade.

In testimony whereof I have hereunto set my hand.

SPENCER HEATH. 

